You're talking about physics in a world where races look like they're pumped on steroids and elves can turn into kittens and bears. It's a cinematic, they're going to do some 'exotic' things with movements. They're teaming up on the panda because at first: he seems like a threat. And who can blame them? He was kicking their asses. He picks up his staff and rice barrel because he's done showing them about what their petty fighting COULD HAVE destroyed, and he's not out to -kill- them, he was getting them to STOP destroying the little area they were in.

Theme of the expansion, really? We already understand it's war, and all of the quests in WoW lead up to war, but like someone else pointed out; The human giving the orc the spear to fight with could be foreshadowing of having to team up against Garrosh at the end.

P.S., It's rude to call people WoW fanboys just because they know a good trailer when they see one.

I'll try to explain why I thought this cinematic was brilliant a perfect fit to the expansion and more importantly, the entire Warcraft universe. Here goes:

The war between the two sides goes all the way back to the first Warcraft game. The factions continued to fight with renewed ferocity in the sequel. In Warcraft 3: Reign of Chaos, we saw the arrival of a powerful common enemy in the Burning Legion. Both sides endured, even joining hands to thwart Archimonde, but the fighting didn't stop. Since then, we've seen plenty of iconic villains like Ragnaros, Nefarian, the Old Gods, Illidan and The Lich King threatening to lay waste to both sides. More recently, we've even had the maniacal Deathwing literally breaking the very world and yet, the fighting hasn't stopped.

Evidently, even the most dangerous super-villains come and go. The only constant in the massive Warcraft universe is of course, the war. Any form of peace turns out to be temporary. The cinematic conveys this brilliantly with the first few lines. Eventually, the war reaches the shores of Pandaria. Enter the Pandaren, who have largely attempted to stay neutral or indifferent in the past. They seem well aware that no matter what they do, the fighting between the two sides won't stop. It will NEVER stop.

The fighting IS Warcraft. Not the heroes, not the villains. It goes back to a much more basic impulse.

The last bits of the cinematic delivers this beautifully. Chen Stormstout looks them both in the eye and smiles, implying that the question for all Pandaren now lies in what they, as individuals believe is worth fighting for: The Alliance's ideals of justice or the Horde's code of honour.

Other than this, to those who consider the cinematic a Kung Fu Panda rip-off: Pandaren Brewmasters precede Kung Fu Panda by five years. They were always melee fighters with a high chance to dodge incoming attacks using their Drunken Haze / Drunken Brawler spells. They certainly borrowed from the Drunken master theme that is popular in Chinese martial art movies but to state Blizzard ripped off Dreamworks is sheer idiocy. The only thing the movie did was popularize the idea of a Panda martial artist.

This cienamtic does nothing to explain what mop is about. The alliance and horde land on pandaria and contiue their battles with one another. The pandaren coming in and subduing them makes everything look confusing.
The only way they could have done this is by showing the entire zone of pandaria filled with conflict brought from bouth sides with the pandaren as the guys who are caught in the middle of it desperatly defending their homes. This show nothing and only adds to the confusion of the overall theme.
Still other than a questinable plot the cinematic quality is top notch as always. Blizzard sure knows how to bring their worlds to life with CGI. While it does not perfectly describe the expantion it still shows the basics off it. Horde Allaince and the Pandaren along with their lands . The only fault is that it could have shown off their new theme much better.

Bad, very bad style, too cartoony...especially the human and the orc, try to put them into the Wotlk cinematic and Lich King would have lol'd..Don't start with wow is cartoony, I have played since first beta, I'm talking about cinematics not ingame graphics! And what about the Belf from TBC cinematic, put her next to MoP cinematic chars...aaargh...orc n human in MoP cinematic are so blocky heads...the orc upper body is 2 times the size of his lower body, i mean WHAT THE F!? Is this WoW or Warhammer!?

Bad, very bad style, too cartoony...especially the human and the orc, try to put them into the Wotlk cinematic and Lich King would have lol'd..Don't start with wow is cartoony, I have played since first beta, I'm talking about cinematics not ingame graphics! And what about the Belf from TBC cinematic, put her next to MoP cinematic chars...aaargh...orc n human in MoP cinematic are so blocky heads...the orc upper body is 2 times the size of his lower body, i mean WHAT THE F!? Is this WoW or Warhammer!?

Orcs have always had huge bulky bodies. Why in the world would you compare the Orc to a Blood Elf, the most waifish of all of the game's races? Try comparing the Draenei in the same cinematic as the Belf to the Orc in the MoP cinematic and the similarities in proportion will be obvious.
Arthas also had proportions quite similar to the human in this cinematic.

Bad, very bad style, too cartoony...especially the human and the orc, try to put them into the Wotlk cinematic and Lich King would have lol'd..Don't start with wow is cartoony, I have played since first beta, I'm talking about cinematics not ingame graphics! And what about the Belf from TBC cinematic, put her next to MoP cinematic chars...aaargh...orc n human in MoP cinematic are so blocky heads...the orc upper body is 2 times the size of his lower body, i mean WHAT THE F!? Is this WoW or Warhammer!?

Hm. A elf sucking up the mana being of a (mana)dragon, next to an Orc and a human, fighting with realistic weapons and techniques?

Oooooh, goood. Seems like a perfectly reasonable argument.
Let's not forget about the super-bouncy raptor troll, or the sheeped Tauren, or the Orc FLYING through the air to cut up naga like it was a hot knife through butter.

Bad, very bad style, too cartoony...especially the human and the orc, try to put them into the Wotlk cinematic and Lich King would have lol'd..Don't start with wow is cartoony, I have played since first beta, I'm talking about cinematics not ingame graphics! And what about the Belf from TBC cinematic, put her next to MoP cinematic chars...aaargh...orc n human in MoP cinematic are so blocky heads...the orc upper body is 2 times the size of his lower body, i mean WHAT THE F!? Is this WoW or Warhammer!?

If you put the Blood Elf from tBC cinematic beside the Orc and Human in the MoP cinematic, she would look like a technical joke. They fit in very well with the style of the game. Hell, for a second I thought that Orc was gonna be Thrall straight from a War3 cinematic.

If anything, I find it amazing how consistent Blizzard has been with their cinematic styles since Warcraft 3.

Look at Thrall and Grom in the Warcraft 3 cinematic depicting Grom's death, and then look at the Orc in the MoP cinematic... yes, the MoP one has cleaner animation and far more detail, but the style is almost unchanged! That's more than impressive, that's an unbelievable feat in and of itself. Warcraft 3 is 10 years old!